Microcom 470 - Manual (Page 21)

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470 Operators Manual 13
CHAPTER 3: COMMUNICATIONS
The 470 is very versatile. It can be interfaced to PC's, mini-computers, main frames, and
special purpose machines. It is capable of serial RS-232-C, Centronics® parallel, and
optionally RS-422/485 serial communication. The following sections explain the communication
interfaces.
Out of the box, unless otherwise requested, the Microcom 470 communicates using serial RS-
232-C at 9600 baud, 8 data bits, 1 stop bit and no parity with both hardware and software
handshaking. This configuration may be changed as shown in Appendix E.
3.1 CABLE PINOUT
Table 1 shows the signals of the 470's 25-pin RS-232 serial port and table 2 shows the parallel
port configuration.
If serial RS-232-C communication is selected and XON/XOFF hand shaking is used, the only
signals the 470 requires are the RXD, TXD, and GND signals. If hardware (CTS) hand shaking
is used, a CTS signal is provided and an RTS signal is required. XON/XOFF may be disabled
through software dip switch #1 (see chapter 5). The other signals are offered in the event the
host computer requires these signals.
Serial Port Configuration
25 TO 9 PIN 25 TO 25 PIN
State 470 Direction PC
HI 8 DCD---->---- DCD 1
XX 3 TXD---->---- RXD 2
XX 2 RXD----<---- TXD 3
HI 20 DTR---->---- DSR 4
LO 7 GND—<->--- GND 5
HI 6 DSR---->---- DTR 6
DC 4 RTS----<---- CTS 7
XX 5 CTS---->---- RTS 8
HI 18 5V
DB-25 DE-9
DC = Do Not Care
XX = Indeterminate
State 470 Direction PC
XX 3 TXD---->---- RXD 3
XX 2 RXD----<---- TXD 2
HI 20 DTR---->---- DSR 6-8
LO 7 GND—<->--- GND 7
HI 6-8 DSR---->---- DTR 20
DC 4 RTS----<---- CTS 4
XX 5 CTS---->---- RTS 5
HI 18 +5V---->---- +5V 18
DB-25 DB-25
DC = Do Not Care
XX = Indeterminate
Table 1